Many technological improvements in window and door design have been made available over the last several years. For instance, the insulating properties of newer window constructions are greatly improved over older window constructions, which can provide a significant energy savings to property owners. Consequently, a significant need has developed to replacing windows and doors during remodeling of older homes and buildings with newer more efficient components.
However, most conventional windows, doors, patio doors, etc. are currently built to standardized dimensions. Since different sizes of windows and doors require differently sized components, it is common practice for manufacturers to offer only a limited number of standardized sizes of windows and doors, which reduces the overall manufacturing complexity and costs of these structures based on the efficiencies obtained through economies of scale.
Many older windows and doors do not conform to standard sizes, and is often difficult to find replacement windows which exactly fit the roughed-in dimensions of a window or a door to be replaced. Therefore, some standard sizes of windows and doors are often not acceptable substitutes as replacement windows. Often, replacement applications may require custom built windows or doors, which typically require individual components to be separately manufactured to size. Consequently, custom window construction does not obtain the benefits of economy to scale, e.g. high volume production of structures used in standardized parts. Thus, many custom windows and doors are significantly more expensive than their standardized counterparts.
Therefore, a need exists for a method of manufacturing windows and doors of custom sizes and shapes which is fast and provides an inexpensive manufacturing process.
A need also exists for improving the manufacturing of standard size windows made from new materials. Many new polymeric and composite materials are being used for the manufacture of standard sized and replacement sized windows, and thus the manufacturing needs for all styles of windows and doors needs to be modified to accommodate these new materials.
Along this line, a need has developed for improved joint structure for joining framing components made from new materials, such as window sashes, window frames, door frames, etc. For example, windows typically require joint structures for sashes which retain a window glass assembly within a frame. A window glass assembly is typically a single pane of glass, or alternatively, a self-contained, multi-paned insulated glass unit whereby two or more panes are stacked and sealed about the perimeters, with a partial vacuum and/or an insulating gas such as argon contained within the sealed space between the panes.
Generally, a sash used to retain a window glass assembly includes framing components which are generally L-shaped in cross-section. A silicone sealant is layered along the inside of the frame, and then the window glass assembly is placed in the frame against the silicone sealant. A glazing bead is then installed around the open side of the sash to retain the window glass assembly therein.
It is also known to include spacer blocks sandwiched between the edges of the window glass assembly and the L-shaped channel in the sash, which forms a condensation channel and centers the pane in the sash. Further, by constructing the sash members of a weldable plastic, it is known that custom sashes may be constructed by miter cutting individual members to size, then butt welding the ends of the sash members together.
Prior to this invention, this butt welding has occurred through heat welding or ultra-sonic welding.
Heat welding involves heating a platen of some type, placing the heated platen in contact with the surface to be welded (oftentimes a thermoplastic material of some type) heating the bonding surface until there is flow, withdrawing the heated platen, and then placing the two bonding surfaces in contact. Thereafter, the heated bonded surface must cool. Heat welding has numerous drawbacks. One drawback is the length of time necessary to heat the welding surfaces to a temperature sufficient for welding. This can take in excess of 30 seconds, which is very slow from a manufacturing point of view when often times millions of units are assembled over the course of a year. Another drawback is if the material which is being welded has good thermal properties, the transfer of heat can be slow so cooling is often slow. The heated surfaces may often experience degradation. Thus a more efficient method of creating a welded joint is needed. Another process for welding window frames is disclosed is U.S. Pat. No. 4,856,230, assigned to Slocomb Industries, which describes a method of securing vinyl window frames together with ultra-sonic welding. U.S. Pat. Nos. 5,105,581, 4,224,091, and 4,090,799 all further discuss the use of ultra-sonic welding techniques in window applications. However, the use of ultra-sonic welding, which requires a horn to be positioned over the weld, whereby the horn admits ultra-sonic frequencies, has numerous drawbacks. In order for an effective weld to take place, often times it is necessary to have multiple horns, with multiple horns for each weld, in that often times with a joint having complex geometry, one horn cannot sufficiently weld the joint portion which is opposite the point farthest from the horn. Further, ultra-sonic welding, although faster than thermal welding involving a heated platen, still suffers from a somewhat slow weld time. A typical ultra-sonic weld may take approximately five or more seconds in order for the weld faces to be melted sufficient such that a weld can occur. A further disadvantage with both thermal heat or ultra-sonic welding is that anytime a thermal plastic material is heated and welded, degradation and excess flash will occur around the weld. As the two faces are bonded together, excess thermoplastic flow occurs which results in the thermoplastic material flowing outside the weld and on the surface of the members which form the weld. This degraded excess flash must be removed in that it diminishes the decorative appearance of the weld. As a general rule, the longer the weld takes to form, the more flash will occur. Thus, it is desirable to produce a weld in a very short period of time, thus minimizing the flash.
There is also a need in the art for a window assembly process whereby sash members may be assembled around a glass assembly in a faster and less expensive manner while having an improved decorative appearance. Welding sash around glass is advantageous in that the sash is ready to be incorporated in a window once the weld is completed. The alternative, which is a slower process, involves forming the sash first, inserting the glass, and sealing the glass in the sash. This results in an operation requiring two or more steps, which again increases the time for manufacture of the product. Thus, there is a need for a process which incorporates the glass and welds the sash members in one quick operation.
There is also a need to quickly weld all types of corners found in the fenestration industry, including but not limited to, mitered corners, mortis and tenon joints, compound mitered corners and non-flush corners just to name a few.
These and other problems associated with the prior art are addressed by the present invention.